Molly Fish

Question

Fish tank  

Black fish   I have 4 new fish all Mollies. The guy at the store said they didn't need a lot of room and that I could keep them all in a 1/2 gallon tank. I have a black, white, speckled and gold one with a black belly that he told me was pregnant. They have no filter, heater, or light in their tank and he told me that was fine. He told me I could use the water from the bag tonight which I did and he told me I could use bottled water instead of buying a filter which is what I was going to switch it to tomorrow. My black and speckled fish were moving around a lot at first but no my black one isn't moving a lot and staying close to the top. The guy told me they didn't need air so why is he doing that. His fins are slicked back but I cant remember if I bought him like that. He keeps twisting to the side but he is still alive. I moved him to a small bowl with bottled water instead of the bag water and tried feeding him but he didn't eat. My other fish are going to the top of the tank then after a while go back to the bottom. Is this normal? Is my black fish sick? How do I help him?

Answer
Kiara,
Unfortunatley, you have learned the hard way that researching the fish before you buy them is a must. You also learned that large pet stores do not train the employees that work in the fish section. EVERYTHING that employee told you is 100% incorrect. 1/2 gallons in not enough water or room for ANY fish, let alone four. To house the 4 mollies that you have now, the minimu size tank is 20 gallons, but a 30 gallon would be better. Mollies are tropical fish and they have to have a heater to stay healthy. They also need a filter. Tap water, and a good conditioner is best for your fish. DO NOT use bottled water. The black fish has clamped fins. This happens when the fish is stressed and/or the water is of bad quality. ALL fish need oxygen in their water. That is what they breathe. For that person to tell you they do not need air is just crazy.
My suggestions are:
1. Get them a 20 gallon tank minimum.
2. Mollies are brackish fish, which means they need salt in their water. Ratio 1 teaspoon of aquarium salt to 1 gallon of water.
3. Get them a filter.
4. They need a heater
5. Add an air stone to their tank.
6. test water daily for ammonia, nitrite, and nitrate. Use a liquid testing kit NOT test strips.
7. If ammonia and/or nitrate is higher than zero, do a water change daily until they are at zero.

If you want your fish to live, you will have to do all of the above.